A variety of different machines are known and widely used for compacting a substrate of material such as paving material and various types of soil. In the context of paving systems, compactors are typically either equipped with metallic cylindrical drums, or pneumatic compacting elements formed from rubber or rubber-like materials. A common practice for certain paving endeavors is to employ multiple compactors in a single paving train.
A first compactor typically follows behind a paver and “breaks down” paving material placed by the paver upon a sub-grade, performing an initial treatment to render the paving material suitable for subsequent work. A second compactor may follow behind the leading compactor and performs what is often described as “kneading” of the paving material, to mix and homogenize the paving material in preparation for working by a finish roller.
Paving material is typically comprised of viscous hydrocarbons, and gravel or the like. The paving material is deposited at a relatively high temperature, and cools to harden into a finished product. It is well known that the hot, viscous hydrocarbon constituents of paving material can stick to machinery in a paving train. Where paving material sticks to ground contacting parts of the machinery, such as the rotating drums or tires of compactors, the quality of the paving material mat can suffer, and continued operation of the machinery can itself be compromised.
Various on-board spray systems configured to spray water, release agents and the like, onto rotating compacting elements are used to prevent the paving material from adhering. One conventional spray system is known in the context of drum compactors, and continuously and autonomously sprays water onto the compacting drums whenever the compactor is moving. Systems are also known for pneumatic compactors which spray water or an emulsion onto the tires. In the case of pneumatic compactors, it is typically unnecessary to continuously spray the tires to prevent sticking of the paving material, and thus the operator is often given control over the spray system to apply the liquid at his/her discretion. While various known systems have been sufficient for many years, there remains ample room for improvement in the manner in which liquid spraying systems for compactors are designed and controlled.